Bruising in non-abused children

Bruising is the commonest injury in children who have been physically abused, but they also sustain bruises from every day activities.

Patterns of bruising do not differ by socio-economic group in non-abused children, and there is no difference bewteen girls and boys. An increase in accidental bruising has been noted in the summer months and with a larger family size (Carpenter 1999; Labbe and Caouette 2001).

Bruising is strongly associated with increased mobility, (Carpenter 1999; Wedgwood 1990) and children sustain more bruises as they become older. Bruising in a baby who is not crawling (with no independent mobility) is very uncommon (in less than 1%) (Sugar et al 1999).

17% of infants who are cruising have bruises (range 1-5), whilst 52% of those who are walking have bruises (mean 5.6, range 1-27 bruises).

In mobile children, the commonest site of bruising is the shins and knees, and most accidental bruises are noted over bony prominences, on the front of the body.

Bruising to the head may be seen in children who are pulling to stand, and who often bump their heads, especially their foreheads (Sugar et al 1999; Tush 1982; Wedgwood 1990; Carpenter 1999).

In addition, ‘Mongolian blue spots’ (McKee et al 2005) are a ‘classic’ mimic for bruising. These are particularly common amongst African or Asian children, and are merely congenital marks on the back, shoulders, shins or ankles etc, and which are often dark blue or violet in colour.

Bruising in abused children

There is no difference between patterns of bruising in boys or girls (Johnson and Showers 1985). Bruises are larger in abused children, and they have more bruises (0-44) (Atwal et al 1998; Dunstan et al 2002).

Bruising is most common on the head, but any part of the body is vulnerable - in particular other sites commonly found to be bruised include the ear, face, neck, trunk, buttocks and arms.

Bruising is the most common injury in physical abuse, but fatal head injuries and fractures can occur without bruising (71% of fatal cases reviewed by Atwal et al (1998) had evidence of new bruising (63% had old bruises, whilst 54% had a combination of fresh and old bruises indicating abuse over an extended time frame) (de Silva and Oates 1993; Dunstan et al 2002; Jappie 1994; Smith and Hanson 1974, Worlock et al 1986).

Where bruising is absent, Atwal et al (1998) speculated that this was due to an insufficient degree of force being applied, gripping being cushioned by clothing, or the disappearance of the bruising by the time of autopsy. Bruising found on those with fatal head injuries is primarily found on the head and face, with lesser amounts on the lower limbs and the buttocks.

Clusters of bruises are common - often defensive injuries on the upper arm, outside of the thigh or bruises on the trunk and adjacent limb. They are often seen on soft parts of the body (in contrast to those in non-abused children) and can be accompanied by scars and/ or abrasions (Brinkmann et al 1979; Sussman 1968; Naidoo 2000).

Bruising to the cheeks and ears was found to be typical of punches and slaps, whilst when they were present, bruises around the ankles were thought to be ‘diagnostic’ of gripping (Atwal et al 1998).

Specific patterns of bruising have been described in abuse cases; vertical gluteal cleft bruising and bruising to the pinna of the ear where the shape assumes the line of anatomical stress, rather than the shape of the injuring object (Feldman 1992; Jappie 1994; Leavitt et al 1992).

When deciding whether bruising was caused as the result of an accident or abuse, the history of the injury may indicate which is the most likely explanation (having regard of the site of the injury, any pattern present, the stage of development of the child and the presence of other (older) injuries etc).

Where the child is mobile, areas overlying bony parts of the body, such as the shins and the forehead are particularly prone to getting knocked accidentally (as any parent will know!), and so judgement must be based on common sense as much as anything else.